An early attempt to fold a short lattice protein (\(N=6\) ) by QA was carried out on a D-Wave (D-Wave Systems Inc.)
machine [1]}. This implementation relied on a growth algorithm, where turns along the chain were mapped onto qubits.
This encoding is resource-efficient for very short chains, but scales exponentially with \(N\) . Recent work implemented on an IBM
gate-based quantum computer used a similar encoding [2]}, again for a short protein chain (\(N=7\) ). These growth
algorithms offer a compact chain representation, at the cost of making interactions such as self-avoidance difficult to implement.
For a recent review of lattice protein folding on quantum computers, see Ref. [3]}.
